CI

At a glance

ClinicalIndex Comparison Record
Phase 1Completed· 551 enrolled / 551 target
Drug / intervention
AltSonflex1-2-3 High Dose +8 morebiological
Likely dose
15 microgramsfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT05073003
NCT05073003Phase 1CompletedHigh Momentum (9.7/mo)Completion was 12mo ago

A Staged Phase I/II Observer-blind, Randomised, Controlled, Multi-country Study to Evaluate the Safety, Reactogenicity, and Immune Responses to the GVGH altSonflex1-2-3 Vaccine Against S. Sonnei and S. Flexneri, Serotypes 1b, 2a, and 3a, in Adults in Europe (Stage 1) Followed by Age De-escalation From Adults to Children and Infants, and Dose-finding in Infants in Africa (Stage 2)

GlaxoSmithKline·interventional·Posted Oct 11, 2021·Updated Jun 22, 2026

In Brief

A Phase 1 clinical trial evaluating AltSonflex1-2-3 High Dose, AltSonflex1-2-3 Medium Dose, and 7 other interventions for Diarrhoea. Completed, enrolled 551 participants across 2 sites in 2 countries.

Signals

Enrolling ahead of pace

Detailed Summary

The aim of the current clinical study was to evaluate, for the first time in humans (FTIH), the safety and immunogenicity of the altSonflex1-2-3 candidate vaccine against S. sonnei and S. flexneri serotypes 1b, 2a, and 3a. The vaccine was first administered to adults 18 to 50 years of age in Europe. Subsequently, the vaccine was administered to a shigellosis-endemic population in Africa, first to adults 18 to 50 years of age, then to children 24 to 59 months of age, and finally to infants 9 months of age. Infants also received a third vaccination. Three different doses of the vaccine \[low, medium, and high amounts of antigen\] were evaluated using an age de-escalation approach (from the least vulnerable adult population to the most vulnerable paediatric population). The results of this study allowed the selection of the most appropriate dose for further vaccine development in infants 9 months of age, which was the main target age group for this vaccine.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsDiarrhoea
CountriesBelgium, Kenya
Collaborators--

Timeline

Phase 1CompletedFinished
20222023202420252026
First PostedOct 11, 2021
Enrollment StartOct 6, 2021
Primary CompletionJun 24, 2025
TodayJul 2, 2026
Enrollment to primary: 3.7 yearsPosted 4.7 years ago

Arms & Interventions

Stage 1 Adults: altSonflex1-2-3 High Dose Group 1experimental

European participants 18-50 years of age were randomized to receive a high dose of altSonflex1-2-3 on Day 1 and Day 85. High dose of altSonflex1-2-3 contained 15 micrograms (µg) of O-antigen (OAg) each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 High Dose
Stage 1 Adults: altSonflex1-2-3 High Dose Group 2experimental

European participants 18-50 years of age were randomized to receive a high dose of altSonflex1-2-3 on Day 1 and Day 169. High dose of altSonflex1-2-3 contained 15 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 High Dose
Stage 1 Adults: Placebo Groupplacebo_comparator

European participants 18-50 years of age were randomized to receive 1 dose of Placebo on Day 1 and on Day 85 or 169. All participants in Step 1 that received placebo were pooled, as pre-specified in Statistical Analysis Plan.

Drug: altSonflex Placebo
Stage 2 Adults: altSonflex1-2-3 High Doseexperimental

African participants 18-50 years of age were randomized to receive a high dose of altSonflex1-2-3 on Day 1 and Day 85. High dose of altSonflex1-2-3 contained of 15 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 High Dose
Stage 2 Adults: Controlactive_comparator

African participants 18-50 years of age were randomized to receive 1 dose of MENVEO as comparator on Day 1 and 1 dose of BOOSTRIX as comparator Day 85.

Biological: MenveoCombination Product: Boostrix
Stage 2 Children: altSonflex1-2-3 Medium Doseexperimental

African participants 24-59 months of age were randomized to receive a medium dose of altSonflex1-2-3 on Day 1 and Day 85. Medium dose of altSonflex1-2-3 contained 7.5 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 Medium Dose
Stage 2 Children: altSonflex1-2-3 High Doseexperimental

African participants 24-59 months of age were randomized to receive a high dose of altSonflex1-2-3 on Day 1 and Day 85. High dose of altSonflex1-2-3 contained 15 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 High Dose
Stage 2 Children: Controlactive_comparator

African participants 24-59 months of age were randomized to receive 1 dose of MENVEO as comparator on Day 1 and 1 dose of TYPHIM VI as comparator on Day 85.

Biological: MenveoCombination Product: Typhim-Vi
Stage 2 Infants safety cohort: altSonflex1-2-3 Low Doseexperimental

African participants 9 months of age were randomized to receive a low dose of altSonflex1-2-3 on Day 1, Day 85 and Day 253. The measles-rubella vaccine (MR-VAC) was administered on Day 29 and Day 281. Low dose of altSonflex1-2-3 contained 3.75 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 Low DoseBiological: MR-Vac
Stage 2 Infants safety cohort: altSonflex1-2-3 Medium Doseexperimental

African participants 9 months of age were randomized to receive a medium dose of altSonflex1-2-3 on Day 1, Day 85 and Day 253. MR-VAC was administered on Day 29 and Day 281. Medium dose of altSonflex1-2-3 contained 7.5 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 Medium DoseBiological: MR-Vac
Stage 2 Infants safety cohort: altSonflex1-2-3 High Doseexperimental

African participants 9 months of age were randomized to receive a high dose of altSonflex1-2-3 on Day 1, Day 85 and Day 253. MR-VAC was administered on Day 29 and Day 281. High dose of altSonflex1-2-3 contained 15 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 High DoseBiological: MR-Vac
Stage 2 Infants safety cohort: Controlactive_comparator

African participants 9 months of age were randomized to receive a dose of MENVEO as comparator on Day 1 and Day 85 and INFRANRIX HEXA as comparator on Day 253. MR-VAC was administered on Day 29 and Day 281.

Biological: MenveoCombination Product: INFANRIX HEXABiological: MR-Vac
Stage 2 Infants dose-finding cohort: altSonflex1-2-3 Low Doseexperimental

African participants 9 months of age were randomized to receive a low dose of altSonflex1-2-3 on Day 1, Day 85 and Day 253. MR-VAC was co-administered on Day 1 and Day 253. This cohort was created to identify the preferred dose among low, medium and high doses. Low dose of altSonflex1-2-3 contained 3.75 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 Low DoseBiological: MR-Vac
Stage 2 Infants dose-finding cohort: altSonflex1-2-3 Medium Doseexperimental

African participants 9 months of age were randomized to receive a medium dose of altSonflex1-2-3 on Day 1, Day 85 and Day 253. MR-VAC was co-administered on Day 1 and Day 253. This cohort was created to identify the preferred dose among low, medium and high doses. Medium dose of altSonflex1-2-3 contained 7.5 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 Medium DoseBiological: MR-Vac
Stage 2 Infants dose-finding cohort: altSonflex1-2-3 High Doseexperimental

African participants 9 months of age were randomized to receive a high dose of altSonflex1-2-3 on Day 1, Day 85 and Day 253. MR-VAC was co-administered on Day 1 and Day 253. This cohort was created to identify the preferred dose among low, medium and high doses. High dose of altSonflex1-2-3 contained 15 µg OAg of each Shigella serotype (S. sonnei, S. flexneri 1b, S. flexneri 2a, S. flexneri 3a).

Biological: AltSonflex1-2-3 High DoseBiological: MR-Vac
Stage 2 Infants dose-finding cohort: Controlactive_comparator

African participants 9 months of age were randomized to receive a dose of MENVEO as comparator on Day 1 and Day 85 and INFRANRIX HEXA as comparator on Day 253. MR-VAC was co-administered on Day 1 and Day 253. This cohort was created to identify the preferred dose among low, medium and high doses.

Biological: MenveoCombination Product: INFANRIX HEXABiological: MR-Vac

Interventions

AltSonflex1-2-3 High Dosebiological

2 doses in adults 18-50 years of age and children 24-59 months of age, 3 doses in infants 9 months of age

AltSonflex1-2-3 Medium Dosebiological

2 doses in children 24-59 months of age, 3 doses in infants 9 months of age

AltSonflex1-2-3 Low Dosebiological

3 doses in infants 9 months of age

Menveobiological

1 dose in adults 18-50 years of age (stage 2) and children 24-59 months of age and 2 doses in infants 9 months of age

Boostrixcombination

1 dose in adults 18-50 years of age (stage 2)

INFANRIX HEXAcombination

1 dose in infants 9 months of age

Typhim-Vicombination

1 dose in children 24-59 months of age

MR-Vacbiological

2 doses in children 24-59 months of age

altSonflex Placebodrug

2 doses in adults 18-50 years of age (stage 1)